Arcuate, stamp down fasteners for sheet securement

ABSTRACT

Improved snap-in fastener devices for securing together panels or sheets of materials such as perforated metal or plastic; arcuate centered, stamp down sheet fasteners adapted to engage the edges of aligned openings through a plurality of stacked sheets in such manner as to securely engage, grip and secure the sheets with respect to one another in the stack; fasteners having a center or central arch or arcuate portion with peripheral flanges engageable with the edges of an opening through the material to be fastened, for example, metal sheets; improved snap-in fasteners comprising integral body members of resiliently deformable yet shape retaining material such as metal or plastic, flanges on at least portions of the periphery of the body member forming one or more grooves therebetween, the body member arcuate in one or more sectional dimension centrally thereof whereby, after the fastener is centered in the opening, a thrusting or punching action causes the arcuate center portion to flatten out so that the fastener rigidly and strongly engages the work with the flanged edges thereof; specific improved flanged, arcuate fasteners of varied shapes including a rectangular shaped fastener with flanges on two opposed edges thereof, a square fastener with flanges on all four side edges thereof, a circular fastener with continuous circumferential flange engagement provided, as well as a fastener of hat shaped configuration; improved snap-in fasteners which are readily removable from engagement with the work by reversal of the snap-in action.

United States Patent [1 1 Wilson [451 Sept. 9, 1975 1 ARCUATE, STAMP DOWN FASTENERS FOR SHEET SECUREMENT Floyd Leroy Wilson, PO. Box 203, Manhattan, Kansl 66502 22 Filed: Oct. 17,1973

[21] Appl.No.:407,064

[76] Inventor:

Primary Examiner-Robert L. Wolfe Assistant Examiner-Doris L, Troutman Attorney, Agent, or FirmThomas M. Scofield [57] ABSTRACT Improved snap-in fastener devices for securing together panels or sheets of materials such as perforated metal or plastic; arcuate centered, stamp down sheet fasteners adapted to engage the edges of aligned openings through a plurality of stacked sheets in such man ner as to securely engage, grip and secure the sheets with respect to one another in the stack; fasteners having a center or central arch or arcuate portion with peripheral flanges engageable with the edges of an opening through the material to be fastened, for example, metal sheets; improved snap-in fasteners comprising integral body members of resiliently deformable yet shape retaining material such as metal or plastic, flanges on at least portions of the periphery of the body member forming one or more grooves therebe tween, the body member arcuate in one or more sectional dimension centrally thereof whereby, after the fastener is centered in the opening, a thrusting or punching action causes the arcuate center portion to flatten out so that the fastener rigidly and strongly engages the work with the flanged edges thereof; specific improved flanged, arcuate fasteners of varied shapes including a rectangular shaped fastener with flanges on two opposed edges thereof, a square fastener with flanges on all four side edges thereof, a circular fastener with continuous circumferential flange engagement provided, as well as a fastener of hat shaped con flguration; improved snap-in fasteners which are readily removable from engagement with the work by reversal of the snap-in action.

14 Claims, 13 Drawing Figures PATENTED 91975 3.903.573

SHEET1UF 2 'IIIIIIIII ARCUATE, STAMP DOWN FASTENERS FOR SHEET SECUREMENT PRIOR ART 1 am aware of the following listed patents relating to snap-in fasteners:

Rapata US. Pat. No. 2,836,215 issued 5-27-58 for Plastic Nut-Like Fastener with Resilient Wings,

OConner US. Pat. No. 3,384,938, issued 5-28-68 for Pliable Material Clamp',

Schuplin US. Pat. No. 3,417,438 issued 12-24-68 for Deformable Polymeric Fastening Deviceg Collyer US. Pat. No. 3,550,217 issued 12-29-70 for Fastener,

Heidelberger U.S. Pat. No. 3,609,822 issued -5-71 for Fastening Device;" and Bowerman US. Pat. No. 3,686,616, issued 8-22-72 for "Fastener.

OBJECTS OF THE INVENTION An object of the invention is to provide novel onepiece fasteners or anchor members.

Another object is to provide novel one-piece fastener members which are adapted to be assembled through apertures of various sizes in work or panel members and securely retained in assembled relationship with such panel members.

Another object of the invention is to provide novel one-piece fastener members which may be economically manufactured by molding in relatively simple split die means.

Another object of the invention is to provide novel one-piece fastener members which are adapted to be received in and lock to panel members or work pieces without requiring complementary fastener members such as screws, bolts or the like.

Another object of the invention is to provide novel one-piece fastener members which may be fabricated of metal or suitable plastic compositions.

Another object is to provide novel one-piece fastener members which are adapted to clamp or retain together various work pieces such as perforated metal, plastic or fiber sheets in assembled relationship with one another.

Another object of the invention is to provide novel clamping and fastening means of one-piece construction adapted to securely snap and secure into place sheet materials of both pliable and rigid materials, thereafter holding said material without slippage or shifting thereof.

Another object of the invention is to provide clamping means for securing perforated sheets of either pliable or rigid material wherein the clamping means is of original arcuate shape, the clamping and securing action being derived from the flattening or straightening out of the originally arcuate device.

Another object of the invention is to provide simple snap-in clamping and fastening means, each form thereof have a minimum number of required parts and of the simplest configuration.

Another object of the invention is to provide a plurality of forms of deformable snap-in arcuate fasteners, same of various shapes and configurations whereby to be adapted to snap-in engagement of openings or apparatures of various configuration, the engagements of limited or circumferential character, depending upon the geometry of the fastener and requirements of the work.

Another object of the invention is to provide a plurality of forms of snap-in fastener devices of varied configuration, same of reliable, simple construction for use in the connection together of sheets or panels of material, the fasteners removable by reversing the snap-in action.

Another object of the invention is to provide an improved unitary, one-piece fastener device readily adaptable for mounting into an apertured work structure same readily useable for connecting or mounting a multiplicity of sheets of material together.

Another object of the invention is to provide such fastener devices which provide satisfactory structural and functional characteristics, which facilitate quick and economic installation and provide permanent stability in the securement of one or more component parts together, particularly in installations where a maximum pull out resistance is required for maintaining a permanent securement.

Another object of the invention is to provide a multiplicity of related yet differing fastener devices which are of simple, rugged, economical to manufacture construction and which are easily and quickly assembled and disassembled with respect to the work with a minimum of time and effort.

Another object of the invention is to provide certain fastener devices which may readily be applied in blind or inaccessible locations and which, because of their improved structural and functional characteristics, provide optimum pull out resistance in the mounted, secured positions thereof.

Another object of the invention is to provide improved fasteners for attachment to one or more apertured work pieces, same basically comprising a shank or snap engagement through the aperture(s) with opposed flanges or heads for abutment against the outer surfaces of the work piece(s).

Another object of the invention is to provide an improved fastener of rectangular shape, said fastener adapted to engage and attach sheet work pieces with flanges on two opposed sides thereof, the fastener arcuate in one transverse section.

Another object of the invention is to provide an improved fastener of circular shape which is adapted to circumferentially engage work piece sheets, the fastener arcuate in section prior to application to the work.

Another object of the invention is to provide a fastener of rectangular shape which is so constructed and configured as to engage by all four sides thereof openings formed in flat work piece sheets.

Another object of the invention is to provide an improved sheet metal fastener having an arcuate portion thereof which is adapted to engage the other side of the work upon depression of the arcuate portion thereof.

Another object of the invention is to provide a fastener of rectangular form having spaced flanges for engaging opposite sides of a multiplicity of work sheets, the fastener provided with an arcuate center section for application of the device to the work.

Other and further objects of the invention will appear in the course of the following description thereof.

In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, embodiments of the invention are shown and, in the various views, like numerals are used to indicate like parts.

FIG. 1 is a three-quarter perspective view from above of a fist form of the subject fastener before application thereof to the work.

FIG. 2 is a cross-sectional view of the fastener of FIG. 1 (longitudinal transverse section).

FIG. 3 is a side elevation of the fastener of FIGS. 1 and 2 as applied to work pieces comprising apertured sheets or panels.

FIG. 3a is a fragmentary top plan of the fastener of FIGS. 1 and 2 engaged with the apertured work pieces.

FIG. 4 is a top plan view of a first modified form of fastener.

FIG. 5 is a view taken along the line 5-5 of FIG. 4 in the direction of the arrows.

FIG. 6 is a side sectional view of the fastener of FIGS. 4 and 5 as applied to the work (the work comprising apertured sheets or panels).

FIG. 7 is a bottom plan view of a second modified form of fastener.

FIG. 8 is a view taken along the line 8-8 of FIG. 7 in the direction of the arrows.

FIG. 9 is a top plan view of a third form of modified fastener.

FIG. 10 is a view taken along the line 10-10 of FIG. 9 in the direction of the arrows.

FIG. 11 is a view like that of FIG. 10, but with the fastener applied to work comprising apertured sheets or panels.

FIG. 12 is a three-quarter perspective view from above of a fourth modified form of the subject fastener.

FASTENER CONSTRUCTION OF FIGS. 1-3, INCLUSIVE The fastener of FIGS. 1-3, inclusive, is of extremely simple configuration, being adapted to engage two 180 opposed edges in a rectangular or square opening formed through a plurality of sheets or panels of metal, wood, plastic or the like. Being rectangular or square, with only two of the four edges of the work being engaged by the opposed flanges of the fastener, the fastener may be so sized that the non-engaged edges of the work abut against the non-flanged sides thereof whereby to at least locate and fix the sheets in position against sliding action with respect to one another.

Referring, then, to FIGS. 1-3, inclusive, at there is generally designated the one piece monolithic construction comprising the fastener. The center portion of the fastener is rectangular in vertical plan view including a top surface 21 (convex prior to application of the work) and a bottom wall 22 (normally concave prior to application to the work). Two nonflanged (or grooved) side edges 23 and 24 extend parallel to one another on the arcuate central body member or portion 21.

Extending from, connected to or integrally formed with the upper surface 21 of member 20 are flanges 21a and 21b. While flanges 21a and 21b may be straight or flat (a smooth continuation of the line of upper surface 21), same are preferably curved outwardly as best seen in FIG. 2. Spaced, opposed, flanges 22a and 22b extend from the inward side and in line with same (22) and preferably are of slightly greater thickness than flanges 21a and 21b. Flanges 21a and 220 thus define therebetween a slot or groove 23 the latter having an inside wall 230, an upper or outer wall 23b and an inner or lower wall 23c. Likewise, between flanges 21b and 22b there is provided notch or groove 24 having inside wall 24a, upper or outer wall 24b and lower or inner wall 24c. The flanges and the grooves or slots formed thereby thus preferably extend the entire width of the rectangular body member.

The upward or outward curving of the upper or outer flanges 21a and 21b are for ease of insertion of the work into the grooves 23 and 24. The purpose of the thickening of the lower or inner flanges 22a and 22b is to prevent a buckling-under effect of said flanges 22a and 2212 when the fastener has been placed into the work piece aperture and is in the process of being applied thereto, as will be described.

A central hole, perforation or opening 25 is optionally provided centrally of the rectangular body member 20. This hole may be circular, oval, (illustrated), square, rectangular or polygonal as desired and is provided for two purposes. In the first place, any suitable punch or similar device or tool may be inserted thereinto for application of the fastener into the work. Subsequently, the same or like tool may be employed in the opposite manner to deform the fastener configuration in the opposite direction to release same from the work.

The device thus comprises a snap-in fastener of resiliently deformable and shape retaining material. This may be metal, plastic, fiberglass in resin, or the like. Same may be integrally molded or stamped of the suitable material, depending on its composition. The structure involves, in the device of FIG. 1-3, incl., the rectangular body member having a pair of spaced apart flanges on each of two opposed edges of the member forming a pair of parallel, spaced apart grooves therebetween. The body member and its flanges are thus normally arcuate in transverse section taken at right angles to the flanges and grooves. With this construction and the resiliently deformable yet shape retaining material making up same, once the body member flanges are initially engaged on the edges of the work member and the center portion thereof is flattened or deformed so that the surfaces 21 and 22 are parallel to one another, the fastener will fully engage with and secure the edges of the work members with respect to one another.

Looking, then, at FIGS. 3 and 3a, therein is seen a pair of sheets, panels or plies of metal, plastic, fiber board, wood, plywood or the like 26 and 27. These sheets 26 and 27 may be of equal or differing thickness, but preferably a combined thickness not substantially greater than the separation of the groove inner walls (23b and 23c). Rectangular openings of congruent form and size are provided through sheets 26 and 27. The length of said openings is preferably equal to the distance between the inside walls 230 and 24a when the surfaces 21 and 22 are parallel as in FIG. 3 and optionally very slightly less to provide a compression connection in a' fastener of suitably deformable material. (Particularly plastic material fasteners.) The width of the openings 28 and 29 must be at least as great as the width of the fastener between its non-flanged sides. If the width of the openings 29 and 28 is greater than the said fastener width by any considerable amount, the sheets 26 and 27 can work or move with respect to one another, sliding within the grooves 23 and 24.

Thus, in application, with the openings 28 and 29 aligned as seen in FIGS. 3 and 3a, the fastener in arcuate form as is seen in FIGS. 1 and 2 is inserted into the openings, one groove first being engaged by one edge of the openings 28 and 29. With this initial engagement, the second groove may be fitted over the opposed edges of sheets 26 and 27 and openings 28 and 29. The curved flanges 21a and 21b facilitate this initial engagement.

Thereafter, the fastener is pressed (downwardly in FIGS. 1 and 2) centrally of the upper or outer surface 21 thereof until the surfaces 21 and 22 are parallel and in alignment as in FIG. 3 in full engagement with the work. The thicker flanges 22a and 22b resist punchthrough or buckling-under of the control portion of the fastener. In this manner, the flanges 21b and 22b closely overlie the outer surfaces of sheets 26 and 27 in sectional engagement therewith with the opening edges 28 and 29 abutting inner wall 24a in groove or slot 24. The same is true with respect to the flanges 21a and 22a and the slot 23 with respect to the opposed opening edges of the sheets 26 and 27.

A plurality of the fasteners engaged in a plurality of openings will secure the work sheets together with greater security and prevent rotation or twisting of same with respect to one another. Some additional security against rotation and twisting of the work pieces could also be obtained by positioning the flanges on the longer side edges of the rectangular fastener.

FASTENER OF FIGS. 4-6, INCLUSIVE Referring to FIGS. 4-6, therein is shown a square fastener having a groove defined by flanges on each of the four edges thereof whereby to engage circumferentially all four edges of square holes in work sheets.

In this modification, there is a rectangular center body 30 having an upper or outer surface 31 and a lower or inner surface 32. The area of upper surface 3] is greater than the area of lower surface 32 as seen in FIG. 5. A circumferential groove 33 extends around and is formed into the body 30 defining the upper surface 31. Four frusto-conical tabs 34-37, inclusive are connected to the peripheral side edges of body portion 30 (or integrally formed or molded therewith), angling downwardly therefrom (in cross-section of the fastener) as is seen at FIG. 5. A pair of spaced apart flanges is provided on each of the tabs or extensions 34-37, inclusive thereby to provide grooves 38-41, inclusive, therein. The outer or upper flanges 34a-37a, inclusive are seen in FIG. 4. Two of the lower flanges 34b and 36b are seen in FIGS. 5 and 6. Tabs or extensions 34-37, inclusive are separate, one from the other.

If desired, a central opening as in the case of opening 25 in the modification of FIGS. 1-3, inclusive, may be provided. Alternatively, as illustrated, a concave depression 310 may be employed to receive a punch. Likewise, the lower or inward flanges (such as 34b and 36b) may be thickened to minimize buckling under or punch-through of the fastener.

In use, this device is initially engaged through the work (sheets 42 and 43 of FIGv 6 having openings 42a and 43a therethrough, respectively) with the lower flanges (such as 3412 and 36h) extending past sheet 43. The arcuate optional curvature of the upper or outer flanges (see 34a and 36a in FIG. 5) aids this insertion and initial engagement. Thereafter, pressure is exerted centrally of the device (downwards in FIG. 5) so that a secure engagement as is seen in FIG. 6 on the work pieces. in the openings thereof, is achieved. To remove, force is exerted in the opposite direction on surface 32 to pop the fastener out of the work sheets.

Thus it may be seen that, before application to the work, the lower or inner side 32, including the lower flanges such as 341) and 36b is normally concave prior to application to the work, while the top surface, including the central top surface 31, the groove 33 and the flanges 34a, is normally convex prior to application to the work. The presence of the circumferential groove 33 and the separate free end edges of the wings, tabs or extensions 34-37, inclusive permit the four side engagement. It should be noted that each one of the wings 34-37, inclusive is separately manipulatable by the applier or user of the fastener to effect the initial engagement of the fastener with the edges of the opening through which the fastener is applied. The groove 33 permits the greater deformation of the top surface under compression.

In each one of the fasteners of FIGS. 1-3, inclusive, 4-6, inclusive and 7 and 8 to be described, the lower or inner flanges may be edged so as to function in a manner similar to a self-punching rivet. That is, bottom cutting flanges would be provided.

FASTENER OF FIGS. 7 AND 8 Referring to the third form of fastener, therein is pro vided a circular central body portion 44 which is arcuate across any section line taken through the center. That is, it is a dished disk having a normally convex upper or outer surface 45 and a normally concave inner or lower surface 46 (both before application to work). Upper and lower flanges 47 and 48, respectively, are provided, forming therebetween a circumferential slot or groove 49. Upper or outer circumferential flange 47 has as its upper surface an arcuate extension of the normally convex upper body surface 45. The lower or inner flange 48 has as its lower or inner face the extension of the arcuate curvature of the concave surface 46. The curvature of surface 46 is preferably greater than that of surface 45, as shown.

If it is desired that the fastener of FIGS. 7 and 8 function as a self-punching rivet, the lower flange may be edged, as seen at 48a, circumferentially. Whether or not the lower flange 48a is edged, it may be thicker than flange 47 for minimization of punch-through or buckling-under. Likewise, a central opening for the same purpose as the opening 25 in FIGS. 1-3, inclusive may be provided. Alternatively, as illustrated, a concave depression 450 may be employed to receive a punch.

In operation or use, the inner or lower flange of the fastener is first engaged through the work and, then, by a central punching action, the center body portion 44 is flattened or depressed so that surfaces 46 and 45 come into parallel, as do the circumferential flanges 47 and 48. Removal of the fastener from its attachment to the work pieces may be accomplished by reversal of this action.

FASTENER OF FIGS. 9-11, INCLUSIVE Referring to FIGS. 9-11, inclusive, therein is shown a fastener of hat-shape form. A hollow centered circular flange 50 has an upper or outer side 50a, an under or lower side 50b and an opening 51 centrally thereof. While the opening Sl is necessarily circular, the peripheral shape of the flange 50 is not critical.

A cylindrical extension 52 is connected at its outer or upper end 52a to (or formed integral therewith) the inner edge of flange 50. The inner or lower edge 52b of cylindrical wall or extension 52 has connected thereto or is formed integrally with an arcuate hemispherical wall 53. Wall 53 has concave (before application of the fastener to the work) inner or under wall 53a and convex outer or upper wall 53b.

In order to fasten a plurality of sheets 54 and 55 together (FIG. 11), the said sheets having one or more circular openings 54a and 55a therethrough to receive such fasteners, the cylindrical wall section 52 is inserted through the openings 54a and 550. With the lower or under side 50b of flange 50 abutting the surface of sheet 54, then, pressuring downwardly wall 53 in FIGS. 10 and 11 results in a circumferential outward expansion or wedging of the lower portion of the wall 52 into locking engagement with the free side of sheet 55 circumferential to its opening 55a. This action may be made with a conventional punch. To remove the fastener, the user drives wall 53 in the opposite direction, namely, to a concave configuration for surfaces 530 by application of a punch or the like to the surface 53a. Alternatively, driving the punch further (particularly a convex ended punch having a diameter substantially that of opening 51) further downwardly in the view of FIG. II will straighten the wall 52 so that the fastener may be pried or pushed out.

FASTENER OF FIG. 12

FIG. 12 shows the fastener concept of FIGS. 1-3, inclusive adapted to an application where a greater thickness of work pieces may be engaged. Referring then to FIG. 12, there is a rectangular shaped body portion (here generally designated 56) centrally positioned of the fastener having a normally concave upper surface 560 (before application to the work pieces), and a normally concave inner or under surface 561). The outer edges 57 and 58 are elongated (or thickened) for at tachment to the work engaging members to be described.

Connected to the thickened edge portions 57 and 58 (or integrally formed therewith) are a pair of U-section members generally designated 59 and 60. U-section member 59 has a U-base or wall 590 to which, at each end thereof, there are connected U-legs 59b and 59c. When legs 59b and 59c are engaged on each side of a plurality of work sheets (as seen with respect to flanges 21b and 22b in FIG. 3) the U-legs 59b and 590 will extend at right angles to the U-base 59a. Prior to this engagement, one or both of the legs 59b and/or 59c may be outwardly angled with respect to U-base 59a. This is seen only in leg 590 in the drawing.

The provision of the U-section member 59 thus pro vides a groove of considerable height 61 between the legs 59b and 59c.

The previously made remarks apply also to the U- section member 60, whereby the parts are numbered with like letters to the parts of the U-section member 59.

In application of the device to the work, not seen in FIG. 12, the flanges 59b and 590, as well as flanges 60b and 60c, respectively, are engaged on opposed edges of apertures in a plurality of stacked work sheets with the center portion 56 of the fastener of FIG. 12 arcuate in form as seen in that view. Once engaged, a punch or like device may be employed to drive arcuate center portion 56 downwardly in the view of FIG. 12, whereby surfaces 56a and 56b become parallel to one another. At this time, if the opposed flanges 60b and 60a (or 59b and 59c) were originally angled (or any of them so originally angled) as seen in FIG. 12, same may be pressed down into flat engagement with the work piece surfaces adjacent the openings therethrough. (In the case of a metal fastener.)

The fastener of FIGS. 4-6 may be fabricated or formed with the body portions 34 and 35 of greater thickness than the body portion 30 whereby to provide wider grooves between the flanges thereon, if desired. Likewise, if the circular fastener of FIGS. 7 and 8 is ra dially slotted in the outer thickened portions thereof, the peripheral portions of the central body 44 may be thickened whereby to space the flanges 47 and 48 further apart to give a greater separation of the work engaging flanges.

To remove the fastener of FIG. 12 from engagement with a plurality of work pieces, the punch is used in the opposite direction as in the removal of the device of the FIGS. 1-3, inclusive modification.

The previously described arcuate stamp-down fasteners particularly adapted for sheet securement, when metal, are applied by means of plastic deformation of the metallic substance. If the fastener is to be made of plastic and thus to be applied by means of plastic deformation, in some instances such may be made out of a thermoplastic material and applied by a heated punch.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

I. A snap-in fastener adapted to removably engage at least two opposed edges of aligned rectangular openings through at least two perforated work member sheets comprising:

a rectangular body member integrally formed of normally shape-retaining yet resiliently deformable material,

a pair of spaced-apart, substantially equal length flanges on each of two opposed edges of said member forming thercbetween a pair of parallel, spaced-apart grooves,

the body member originally arcuate in transverse section taken at right angles to said flanges and grooves before application to the work members to be secured with respect to one another,

whereby, when the body member flanges are initially engaged on edges of aligned openings through said work members and the center thereof is flattened, the fastener will fully engage the edges of the work member aligned openings and secure the said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.

2. A fastener as in claim 1 wherein one of each set of flanges is curved outwardly and the other of each set of flanges is of greater thickness than the others the flanges of greater thickness on the originally concave side of the body member.

3. A snap-in fastener adapted to removably engage all four edges of aligned square openings through at least two perforated work member sheets, comprising a square body member integrally formed of resiliently deformable yet shape retaining material,

said body member having a square central portion with parallel upper and lower walls,

the lower wall of lesser dimension than the upper wall,

four frusto-conical extensions each integrally connected with one edge of said central portion and angled downwardly with respect thereto,

a pair of spaced apart substantially equal length flanges on each of two opposed edges of each set of opposed frusto-conical extensions forming a pair of parallel, spaced apart grooves therebetween on said fastener,

the body member thus normally arcuate in transverse section taken at right angles to each set of flanges and grooves,

whereby, when the frusto-conical extension flanges are initially engaged on edges of work members and the square body member is pushed into line with the extensions and the work members engaged, the fastener will fully engage on all four sides thereof and secure the edges of said work members with respect to one another.

4. A snap-in fastener adapted to removably engage all four edges of aligned, square openings through at least two perforated work member sheets comprising:

a square body member integrally formed of normally shape'retaining yet resiliently deformable material,

said body member having a square central portion with parallel upper and lower walls, with the lower wall of said central portion of lesser dimension than the upper wall thereof,

four frusto conical extensions each integrally connected with one edge of said central portion and angled downwardly with respect thereto,

a pair of spaced-apart, substantially equal length flanges on each of two opposed edges of each set of opposed, frusto-conical extensions forming therebetween a pair of parallel, spaced apart grooves,

the body member thus originally arcuate in transverse section taken at right angles to each set of flanges and grooves before application to the work members to be secured with respect to one another,

whereby, when the frustoconical extension flanges are initially engaged on edges of aligned openings through said work members and the square body member is pushed into line with the extensions, the fastener will fully engage the edges of the work member aligned openings on all four sides thereof and secure said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.

5. A fastener as in claim 4 including a circumferential groove formed in the edge of the greater dimension upper wall of the square body member adjacent to the connection of the frusto-conical extensions thereto on the originally convex side of the fastener.

6. A device as in claim 4 wherein one of each set of flanges is curved outwardly and the other of each set of flanges is of greater thickness than the other the flanges of greater thickness on the originally concave side of the body member.

7. A snap-in fastener as in claim 4 including a central recess in the originally convex side of said square body member.

8. A snap-in fastener adapted to removably circumferentially engage the edges of aligned circular openings through at least two perforated work member sheets comprising:

a circular body member integrally formed of normally shape retaining yet resiliently deformable material,

a pair of spaced-apart, substantially equal length flanges on the peripheral edge of said member forming a circumferential groove therebetween,

the circular body member originally arcuate in transverse section throughout before application to the work members to be secured with respect to one another,

whereby, when the body member flanges are initially engaged on edges of aligned openings through said work members and the center thereof is flattened into the plane of the work members engaged, the fastener will fully and circumferentially removably engage the edges of the work member aligned openings and secure said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.

9. A fastener as in claim 8 where one of said flanges is curved outwardly and the other said flange is of greater thickness, the flange of greater thickness on the originally concave side of the body member.

10. A fastener as in claim 8 including a central recess in the originally convex side thereof.

11. A snap-in fastener adapted to removably engage at least two opposed edges of aligned rectangular openings through at least two perforated work member sheets comprising:

a rectangular body member integrally formed of normally shape retaining yet resiliently deformable material,

said body member originally arcuate in transverse section before application to the work members to be secured with respect to one another,

a flat based, U-shaped (in side section) member connected to each of two opposed edges of said body member at the non-curved ends of same,

the legs of the U-shaped members extending at substantial right angles to the base of each U-shape member,

and the connection of the body member edges being to the flat bases of the U with the U-legs extending outwardly and away therefrom,

whereby, when the legs of the U-shaped members are initially engaged on edges of aligned openings through said work members and the arcuate body member is flattened into the plane of the engaged work members, the fastener will fully engage the edges of the work member aligned openings and secure said work members with respect to one an other, with the formerly arcuate body section in line with the engaged work member.

leg of the U in each case, with the U base being thickened at said juncture.

14. A fastener as in claim 11 wherein one of each of said U member legs is outwardly angled. 

1. A snap-in fastener adapted to removably engage at least two opposed edges of aligned rectangular openings through at least two perforated work member sheets comprising: a rectangular body member integrally formed of normally shaperetaining yet resiliently deformable material, a pair of spaced-apart, substantially equal length flanges on each of two opposed edges of said member forming therebetween a pair of parallel, spaced-apart grooves, the body member originally arcuate in transverse section taken at right angles to said flanges and grooves before application to the work members to be secured with respect to one another, whereby, when the body member flanges are initially engaged on edges of aligned openings through said work members and the center thereof is flattened, the fastener will fully engage the edges of the work member aligned openings and secure the said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.
 2. A fastener as in claim 1 wherein one of each set of flanges is curved outwardly and the other of each set of flanges is of greater thickness than the others the flanges of greater thickness on the originally concave side of the body member.
 3. A snap-in fastener adapted to removably engage all four edges of aligned square openings through at least two perforated work member sheets, comprising a square body member integrally formed of resiliently deformable yet shape retaining material, said body member having a square central portion with parallel upper and lower walls, the lower wall of lesser dimension than the upper wall, four frusto-conical extensions each integrally connected with one edge of said central portion and angled downwardly with respect thereto, a pair of spaced apart substantially equal length flanges on each of two opposed edges of each set of opposed frusto-conical extensions forming a pair of parallel, spaced apart grooves therebetween on said fastener, the body member thus normally arcuate in transverse section taken at right angles to each set of flanges and grooves, whereby, when the frusto-conical extension flanges are initially engaged on edges of work members and the square body member is pushed into line with the extensions and the work members engaged, the fastener will fully engage on all four sides thereof and secure the edges of said work members with respect to one another.
 4. A snap-in fastener adapted to removably engage all four edges of aligned, square openings through at least two perforated work member sheets comprising: a square body member integrally formed of normally shape-retaining yet resiliently deformable material, said body member having a square central portion with parallel upper and lower walls, with the lower wall of said central portion of lesser dimension than the upper wall thereof, four frusto-conical extensions each integrally connected with one edge of said central portion and angled downwardly with respect thereto, a pair of spaced-apart, substantially equal length flanges on each of two opposed edges of each set of opposed, frusto-conical extensions forming therebetween a pair of parallel, spaced apart grooves, the body member thus originally arcuate in transverse section taken at right angles to each set of flanges and grooves before application to the work members to be secured with respect to one another, whereby, when the frusto-conical extension flanges are initially engaged on edges of aligned openings through said work members and the square body member is pushed into line with the extensions, the fastener will fully engage the edges of the work member aligned openings on all four sides Thereof and secure said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.
 5. A fastener as in claim 4 including a circumferential groove formed in the edge of the greater dimension upper wall of the square body member adjacent to the connection of the frusto-conical extensions thereto on the originally convex side of the fastener.
 6. A device as in claim 4 wherein one of each set of flanges is curved outwardly and the other of each set of flanges is of greater thickness than the other the flanges of greater thickness on the originally concave side of the body member.
 7. A snap-in fastener as in claim 4 including a central recess in the originally convex side of said square body member.
 8. A snap-in fastener adapted to removably circumferentially engage the edges of aligned circular openings through at least two perforated work member sheets comprising: a circular body member integrally formed of normally shape retaining yet resiliently deformable material, a pair of spaced-apart, substantially equal length flanges on the peripheral edge of said member forming a circumferential groove therebetween, the circular body member originally arcuate in transverse section throughout before application to the work members to be secured with respect to one another, whereby, when the body member flanges are initially engaged on edges of aligned openings through said work members and the center thereof is flattened into the plane of the work members engaged, the fastener will fully and circumferentially removably engage the edges of the work member aligned openings and secure said work members with respect to one another, with the formerly arcuate body section in line with the engaged work members.
 9. A fastener as in claim 8 where one of said flanges is curved outwardly and the other said flange is of greater thickness, the flange of greater thickness on the originally concave side of the body member.
 10. A fastener as in claim 8 including a central recess in the originally convex side thereof.
 11. A snap-in fastener adapted to removably engage at least two opposed edges of aligned rectangular openings through at least two perforated work member sheets comprising: a rectangular body member integrally formed of normally shape retaining yet resiliently deformable material, said body member originally arcuate in transverse section before application to the work members to be secured with respect to one another, a flat based, U-shaped (in side section) member connected to each of two opposed edges of said body member at the non-curved ends of same, the legs of the U-shaped members extending at substantial right angles to the base of each U-shape member, and the connection of the body member edges being to the flat bases of the U with the U-legs extending outwardly and away therefrom, whereby, when the legs of the U-shaped members are initially engaged on edges of aligned openings through said work members and the arcuate body member is flattened into the plane of the engaged work members, the fastener will fully engage the edges of the work member aligned openings and secure said work members with respect to one another, with the formerly arcuate body section in line with the engaged work member.
 12. A fastener as in claim 11 wherein the width of the U-shaped member base is greater than the height of the arch in the arcuate body member.
 13. A snap-in fastener as in claim 11 wherein the edge connections of the arcuate rectangular body member to the U-shaped member bases is adjacent one leg of the U in each case, with the U base being thickened at said juncture.
 14. A fastener as in claim 11 wherein one of each of said U member legs is outwardly angled. 